[carrollcw]

Ok, so I should have noticed this earlier, but after mounting my engine, fitting my cowl, and starting the baffle fit, I just realized, I have an engine with forward facing horizontal induction but have the vans cowl designed for bottom facing vertical induction (the one with the snorkel). I also have a cold sump when I was planning on a warm sump. So my main problem is, I can't get filtered air to my intake because the snorkel is way too low for a horizontal induction engine!

So, as I see it, I have 3 options:

1- get a new cowl designed for horizontal induction
2- have the sump and induction replaced
3- modify my cowl for bower ram air

If I do 1- will I only need to order the lower half? What effect will this have on my baffle ramps?

If I do 2- major pain. Don't really want to mess with a brand new engine.

If it do 3- I have an exhaust problem. The vetterman exhaust for the cold sump does not fit the vans cowl with the snorkel. Is there an exhaust system that will fit? Also the ram system is over $1000. Is it worth it?

Thanks in advance for the help. This is a HUGE problem!

 

[RV7A Flyer]

If you haven't drilled or cut the cowling, Van's will probably exchange it. I had this problem when I was going to go with a Superior engine and then they went out of business, so I switched to Lycoming. Van's was very good about just exchanging the cowling, but I hadn't done any modifications to it at all.

 

[RV7A Flyer]

I have an engine with forward facing horizontal induction but have the vans cowl designed for bottom facing vertical induction (the one with the snorkel).

Just as an aside, the "snorkel" usually, AFAIK, refers to the horizontal induction and the attached fiberglass part that goes up to the inlet ramp. I don't know what they call that protrusion on the lower cowling for the bottom-facing (vertical) induction setups...

Anyway, just to avoid confusion if you're talking with Van's or other vendors...

You might also find someone here on VAF who is willing to swap. I swapped wingtips with somebody who wanted the new ones, and I wanted the older "batwings". Good deal for everybody...

Best of luck...

 

[Scott Hersha]

Yes. Simple answer is, get the correct cowling, even if it costs you some $. Then press on and finish your airplane. I think #1 is your most viable option.

 

[Ironflight]

Just as an aside, the "snorkel" usually, AFAIK, refers to the horizontal induction and the attached fiberglass part that goes up to the inlet ramp. I don't know what they call that protrusion on the lower cowling for the bottom-facing (vertical) induction setups...

Accepted terminology for that protrusion on the bottom of a cowl designed for vertical induction is the "Snout".....

 

[rvbuilder2002]

Just as an aside, the "snorkel" usually, AFAIK, refers to the horizontal induction and the attached fiberglass part that goes up to the inlet ramp.

Correct.
The common definition of a snorkle is something used to supply air from above.

Unless you are interested in doing a lot of hours modifying/making things work, I also would suggest you get the correct bottom cowl.

 

[Walt]

Correct.
The common definition of a snorkle is something used to supply air from above.

Unless you are interested in doing a lot of hours modifying/making things work, I also would suggest you get the correct bottom cowl.

Correct me if I'm wrong but I believe the "snout" O360 cowl is narrower in the front than the "snorkle" IO360 cowl, so you would need both upper and lower cowls.

 

[MikeyDale]

Been there, done that!

I did surgery on mine. Fact is, I bought my project and the cowl had already been partially fitted for another engine so I could not exchange it or swap with someone. I wanted horizontal induction and purchased the sump and snorkle kit and had it ready to go and realized I had the wrong cowl!......

I kept the very bottom of the cutout and formed it up with packing tape.

Then layed it up with glass cloth.

Then filled, sanded, and shaped. Then I had to cut out and add a Bubble because the heat muffler was too close!

It turned out OK but you cant really see it that well in this pic.

[/IMG]

I learned a lot about fiber glassing with this little project but I could have save a huge amount of time if I could have swapped cowls for a smooth one or just plugged the snout!

 

[BillL]

Ok, so I should have noticed this earlier, but after mounting my engine, fitting my cowl, and starting the baffle fit, I just realized, I have an engine with forward facing horizontal induction but have the vans cowl designed for bottom facing vertical induction (the one with the snorkel). I also have a cold sump when I was planning on a warm sump. So my main problem is, I can't get filtered air to my intake because the snorkel is way too low for a horizontal induction engine!

So, as I see it, I have 3 options:

1- get a new cowl designed for horizontal induction
2- have the sump and induction replaced
3- modify my cowl for bower ram air

If I do 1- will I only need to order the lower half? What effect will this have on my baffle ramps?

If I do 2- major pain. Don't really want to mess with a brand new engine.

If it do 3- I have an exhaust problem. The vetterman exhaust for the cold sump does not fit the vans cowl with the snorkel. Is there an exhaust system that will fit? Also the ram system is over $1000. Is it worth it?

Thanks in advance for the help. This is a HUGE problem!

You certainly have listed the most expensive ($ wise) options. One that is not listed is make a custom airlifted box like DanH did for his 8. You could use his methods and general design with a lower offset exit for the plate type airfilter element. His is low pressure drop and incorporates a spring loaded (and closing) emergency air bypass. It has been flow tested. So this is the expensive (labor wise) option not on the list. I would do this before buying a new lower cowl. (probably why I am not finished)

I will add the link when I find it. OK - - http://www.vansairforce.com/community/showthread.php?t=44856&page=2

 

[RVbySDI]

Ok, so I should have noticed this earlier, but after mounting my engine, fitting my cowl, and starting the baffle fit, I just realized, I have an engine with forward facing horizontal induction but have the vans cowl designed for bottom facing vertical induction (the one with the snorkel). I also have a cold sump when I was planning on a warm sump. So my main problem is, I can't get filtered air to my intake because the snorkel is way too low for a horizontal induction engine. . .

Yes, you can get filtered air to the engine, just not with the cowl setup you currently have. Here is a pic during construction of the "snorkel" being fitted to my forward facing cold air induction ECI IO-340:

Correct me if I'm wrong but I believe the "snout" O360 cowl is narrower in the front than the "snorkle" IO360 cowl, so you would need both upper and lower cowls.

Walt is correct, the IO360 cowl you will need to use is wider than the standard "snout" cowl. You will have to go with a new top and bottom cowl but as others have stated contact Vans. They will trade out what you have with what you need as long as you have not modified the cowl already. Here is a pic of the bottom cowl off of the plane. Disregard the arrow, this was a pic I posted on a different topic.

Here is what the cowl looks like without the "snout" and the IO-360 cowl finished:

If it do 3- I have an exhaust problem. The vetterman exhaust for the cold sump does not fit the vans cowl with the snorkel. Is there an exhaust system that will fit? Also the ram system is over $1000. Is it worth it?

Vetterman has a couple of options now for the forward facing sump. I have gone with Vetterman's 4 straight pipe setup. It fit like it belonged. He also has a new "trombone" design that he states would work with the forward facing sumps. It looks like a good design. Give Clint a call at Vetterman.

You can just see the "snorkel" in front of the intake and exhaust in this pic taken looking up from underneath the engine. You might also take note of the throttle cable visible in this pic. If you go this route you will need to redirect that cable which will require a different length, and design, from what Vans provides in the Firewall Forward Kit. I ordered this cable from Aircraft Spruce, just to let you know it is not a problem, just different than what is provided.

Here are the pipes coming out the bottom of the cowl:

Hope this info helps.

 

[carrollcw]

Just to clarify, my cowl has already been cut and drilled.

Thanks for the help. After talking to Clint and Kevin, Right now I am leaning towards swapping the sump and induction out.

 

[kiwipete]

Which exhaust do you have?

A different sump will require a different exhaust. So you need to ensure you have the correct exhaust for either the horzontal or vertical injection sumps.

Peter

 

[Ironflight]

Just a datapoint for you Clark - when building the -3, we found we had to change the cowling because of our engine choice. Van's swapped us even-up for the replacement ( we hadn't touched it) and Partain had a truck coming through Houston, so they threw it on there, and Partain asked me to give the drive $50 to drop off the new one and pick up the old. So it didn't' cost much, took just a couple of weeks (you can find lots of other things to work on) - and they know the way to Polly Ranch!

Paul

 

[SHIPCHIEF]

I've been thru the cowl mod process a couple of times.
First I installed a Mazda Rotary, so I had to make a radiator scoop and an oil cooler air exit. Then I had an exhaust leak from failed turbocharger fasteners, so I had to make a repair.
Finally (so far) I converted to a stock O-360 configuration and selected the Superior cold sump + Vetterman cross over exhaust.
I had to remove the radiator scoop and glass in the big hole on the bottom, then cut a new hole for my own direct ram intake. I used modelling clay to form the new intake fairing, similar to making landing gear intersect fairings.
It was not difficult, just took a week. Start by searching the forums and reading what Dan H says about fiberglass. His posts are a catalyst for other creative builders who add additional ideas.
Pictures of my cowl can be seen on the link in my signature line.